Siemens SIMATIC RF640A, Системное руководство

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Safety Information
2.3 Safety distance to transmitter antenna
SIMATIC RF600
20
System Manual, 11/2018, J31069-D0171-U001-A21-7618
Note
User responsibility for modified product
As a user of the modified product, you accept responsibility for use of the complete RFID
product comprising both SIMATIC RF600 components and third-party RFID components.
This particularly applies to modification or replacement of:
• Antennas
•
Antenna cables
•
readers
•
Power supply units with connection cables
2.3 Safety distance to transmitter antenna
2.3.1 Safety distance between transmitter antenna and personnel
For antenna configurations where it is possible to be briefly or constantly within the
transmission range of the antennas, as in loading ramps, for example, minimum distances
must be maintained.
Limits
The ICRP (International Commission of Radiological Protection) has worked out limit values
for human exposure to HF fields that are also recommended by the ICNIRP (International
Commission of Non Ionizing Radiological Protection). In German legislation on emissions
(since 1997), the following limit values apply. These can vary according to frequency:
Frequency f [MHz] Electrical field strength E [V/m] Magnetic field strength H [A/m]
10 - 400 27,5 0,073
400 - 2.000 1.375 x f
1/2
0.0037 x f
1/2
2.000 - 300.000 61 0,16
The limit values for the 900 MHz reader antenna alternating field are thus:
Electrical field strength: E = 41.25 V/m
Magnetic field strength: H = 0.111 A/m
HF power density: E x H = 4.57 W/m
2